A month ago my key started to only work in the ignition intermittently; the short is that the "wafers" were going bad in the cylinder. The dealer said it would cost $250+ to replace it but I should be fine for a while. Of course we were about to go on vacation....
At mile/exit 77 on US59 with 3.5 hours to home and the key wouldn't work. (Oh, and did I mention a 7 year old and an 18 month old with us and that we were 17 hours into the 20+ hour drive?

)
The truckers at the stop were very nice and our collective wisdom decided to call a locksmith. Short story made long: $50 later the lock smith had cleaned out and fixed the ignition cylinder and all was and is well!
Hope that helps some folks!
Cb